Using CT to evaluate mediastinal great vein invasion by thymic epithelial tumors: measurement of the interface between the tumor and neighboring structures.

OBJECTIVES: For thymic epithelial tumors, simple contact with adjacent structures does not necessarily mean invasion. The purpose of our study was to develop a simple noninvasive technique for evaluating organ invasion using routine pretreatment computed tomography (CT). METHODS: This retrospective study analyzed the pathological reports on 95 mediastinal resections performed between January 2003 and June 2020. Using CT images, the length of the interface between the primary tumor and neighboring structures (arch distance; Adist) and maximum tumor diameter (Dmax) was measured, after which Adist/Dmax (A/D) ratios were calculated. Receiver operating characteristic (ROC) curves were used to analyze the Adist and A/D ratios. RESULTS: An Adist cut-off of 37.5 mm best distinguished between invaded and non-invaded mediastinal great veins based on ROC curves. When Adist > 37.5 mm was used for diagnosis of invasion of the brachiocephalic vein (BCV) or superior vena cava (SVC), the sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and area under the ROC curve for diagnosis of invasion were 61.9%, 92.5%, 81.25%, 82.2%, 81.97%, and 0.76429, respectively. Moreover, there were significant differences between BCV/SVC Adist > 37.5 mm and ≤ 37.5 mm for 10-year relapse-free survival and 10-year overall survival (p < 0.01). CONCLUSIONS: When diagnosing invasion of the mediastinal great veins based on Adist > 37.5 mm, we achieved a higher performance level than the conventional criteria such as irregular interface with an absence of the fat layer. Measurement of Adist is a simple noninvasive technique for evaluating invasion using CT. Key Points • Simple contact between the primary tumor and adjacent structures on CT does not indicate direct invasion. • Using CT images, the length of the interface between the primary tumor and neighboring structures (arch distance; Adist) is a simple noninvasive technique for evaluating invasion. • Adist > 37.5 mm can be a supportive tool to identify invaded mediastinal great veins and surgical indications for T3 and T4 invasion by thymic epithelial tumors.

Effects of localisation of uterine adenomyosis on outcome of in vitro fertilisation/intracytoplasmic sperm injection fresh and frozen-thawed embryo transfer cycles: a multicentre retrospective cohort study.

BACKGROUND: Uterine adenomyosis is a benign disease, common among women in their 40 and 50 s, characterised by ectopic endometrial tissue in the uterine myometrial layer. Adenomyosis causes infertility and has a negative effect on the outcomes of in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) embryo transfer (ET) cycles. It has also been reported to have different characteristics depending on the adenomyotic lesion localisation. The effect of its localisation on IVF/ICSI-ET outcomes is unclear. This study aimed to investigate whether adenomyotic lesion localisation, assessed using magnetic resonance imaging (MRI), was associated with outcomes of IVF/ICSI-ET cycles. METHODS: This multicentre, joint, retrospective cohort study analysed the medical records of 67 infertile patients with adenomyosis who underwent IVF/ICSI with fresh and frozen-thawed ET at five participating facilities from January 2012 to December 2016 and for whom MRI data were available. Fifteen patients were excluded; therefore, the MRI data of 52 patients were evaluated by two radiologists. We assessed the localisation of and classified adenomyotic lesions into advanced (invades the full thickness of the uterine myometrium), extrinsic (localised on the serosal side), and intrinsic (localised on the endometrial side) subtypes. RESULTS: There were 40 advanced, nine extrinsic, and three intrinsic cases, and the outcomes of 100, 27, and nine ET cycles, respectively, were analysed. Pregnancy loss/clinical pregnancy and live birth rates of the advanced, extrinsic, and intrinsic groups were 64 % (16/25) and 9 % (9/100), 33.3 % (3/9) and 22.2 % (6/27), and 50 % (1/2) and 11.1 % (1/9), respectively. A logistic regression analysis adjusted for age, prior miscarriage, and body mass index showed that the extrinsic group had fewer pregnancy losses (odds ratio 0.06; 95 % confidence interval [CI]: 0.00-0.54, p = 0.026) and more live births (odds ratio 6.05; 95 % CI: 1.41-29.65, p = 0.018) than the advanced group. CONCLUSIONS: Adenomyotic lesions exert different effects on IVF/ICSI-ET outcomes. Thus, MRI assessments of adenomyosis in infertile patients are beneficial. Establishment of treatment plans based on adenomyotic lesion localisation should be considered.

Diffusion-weighted MRI for differential diagnosis in gallbladder lesions with special reference to ADC cut-off values.

BACKGROUND/AIMS: We retrospectively evaluated the usefulness of the apparent diffusion coefficient (ADC) measured from high-b value diffusion-weighted imaging (DWI) of magnetic resonance imaging for the differential diagnosis of gallbladder lesions among patients with cancer, adenoma and inflammatory disease. METHODOLOGY: Forty patients with gallbladder lesions (22 patients with cancer, 7 patients with adenoma, and 11 patients with inflammatory disease) were enrolled in this study. All patients underwent high-b value DWI, and the ADC value was measured. The cut-off values were determined by receiver operating characteristic analysis. RESULTS: The ADC values of gallbladder cancers (1.31±0.57x10-3 mm2/s) were smallest and those of adenomas (2.66±0.43x10-3 mm2/s) were largest among the diseases. Inflammatory diseases took a middle position (1.97±0.54x10-3 mm2/s) between them. There were significant differences among the 3 groups of diseases (p<0.05). The cut-off value within ADC values to discriminate cancer from the other diseases was 1.64x10-3 mm2/s (accuracy 87.5%), and that to discriminate adenoma was 2.25x10-3 mm2/s (accuracy 90.0%). CONCLUSIONS: The ADC values measured from high-b value DWI would be useful for the differential diagnosis of gallbladder lesions.

Outcomes of patients receiving additional esophagectomy after endoscopic resection for clinically mucosal, but pathologically submucosal, squamous cell carcinoma of the esophagus.

PURPOSE: This study investigated the actual rate or extent of lymph node metastasis or the survival outcomes among patients that underwent esophagectomy with lymph node dissection after ESD for clinical mucosal, but pathological submucosal, esophageal cancer. METHODS: Seventeen patients that received esophagectomy with two- or three-field lymph node dissection as additional treatment after ESD for clinical mucosal, but pathological submucosal, esophageal cancer between 2006 and 2010 were analyzed. The rate and extent of lymph node metastasis and the patient outcomes were determined. RESULTS: The tumor depths were diagnosed as SM1 in 8 (47 %) patients and SM2 in 9 (53 %), based on the analyses of resected specimens. Lymphatic invasion was evident in 13 (76 %) patients, while venous invasion was detected in 5 (29 %). Five (29 %) patients had pathologically detected lymph node involvement. Seven (0.8 %) of the 890 dissected nodes showed cancer involvement. Three patients had one involved node in the mediastinum or abdomen, and 2 patients had 2 involved nodes in the abdomen. The patients were followed up for 11-71 months (median 23 months), and all were alive without recurrence at the final follow-up. CONCLUSION: Twenty-nine percent of the patients diagnosed with clinically mucosal, but pathologically submucosal, thoracic squamous cell esophageal cancer after ESD had 1-2 cancer-involved lymph nodes in the lower mediastinum and abdomen. Esophagectomy with lymph node dissection is therefore considered to be a necessary and effective additional treatment for these patients.

Correlation between severity of carotid stenosis and vascular reserve measured by acetazolamide brain perfusion single photon emission computed tomography.

Few studies have investigated the relationship between the degree of stenosis of the internal carotid artery (ICA) and cerebrovascular reserve (CVR). This study examined that relationship. A total of 56 ICAs in 43 patients were included. Computed tomography scan or magnetic resonance imaging showed no evidence of infarction in any of these patients. Both iodine-123-N-isopropyl-p-iodoamphetamine ((123)IMP)-single photon emission computed tomography (SPECT) in the resting state and (123)IMP-SPECT with acetazolamide (ACZ) enhancement were performed. Quantitated cerebral blood flow (CBF) images were acquired with the (123)IMP autoradiography technique. The mean CBF without ACZ administration (resting CBF) and CVR in the middle cerebral artery territory were calculated using stereotactic extraction estimation (SEE) analysis software. The degree of stenosis in the origin of the ICA was calculated from intra-arterial digital subtraction angiography. Resting CBF was not correlated with the degree of ICA stenosis; however, nonlinear regression analysis (second-order equation) showed a moderate correlation between CVR and the degree of ICA stenosis. In 72% of the cases with a CVR <30%, ICA stenosis was >74%. Using the SEE method, CVR was moderately correlated with the degree of ICA stenosis. Our findings indicate that evaluating CVR by ACZ-enhanced (123)IMP-SPECT in patients with ICA stenosis is of clinical value.

Estimating the need for neck lymphadenectomy in submucosal esophageal cancer using superparamagnetic iron oxide-enhanced magnetic resonance imaging: clinical validation study.

BACKGROUND: In cases of thoracic esophageal cancer, multidirectional lymphatic flow from the tumor means that lymph node metastasis can occur in an area extending from the neck to the abdomen. To validate a method for limiting the performance of three-field lymphadenectomy only to patients who need it, we carried out a prospective study in which superparamagnetic iron oxide (SPIO)-enhanced lymphatic mapping was used to determine whether to perform neck lymph node dissection in patients with submucosal thoracic esophageal cancer. METHODS: A total of 22 patients with clinically submucosal thoracic squamous cell esophageal cancer, without neck lymph node metastasis, were enrolled. SPIO was endoscopically injected into the peritumoral submucosal layer, after which its appearance in lymph nodes in the neck was evaluated using magnetic resonance imaging (MRI). Neck lymph nodes were then dissected based on the SPIO-enhanced MRI lymphatic mapping. RESULTS: Influx of SPIO into lymph nodes was detected in 21 patients (95% detection rate). SPIO flowed to the neck in 8 (36%) patients. Influx of SPIO into neck lymph nodes was unilateral in five patients and bilateral in three patients, and the lymph nodes were dissected accordingly. A cancer-involved node was identified in two of those patients. In 14 patients, we did not dissect neck nodes. Patients were followed up for 6 to 47 months. The neck lymph node recurrence rate was zero, and the overall recurrence rate was 5%. CONCLUSIONS: SPIO-enhanced lymphatic mapping may be useful for estimating the need for three-field lymphadenectomy with neck dissection.

Glioblastoma, IDH-wildtype with leptomeningeal metastasis to Meckel's cave: A case report.

Meckel's cave or the trigeminal cistern is a subarachnoid space near the apex of the petrous portion of the temporal bone and contains cerebrospinal fluid and the Gasserian ganglion, which divides into the ophthalmic (V1), maxillary (V2), and mandibular (V3) nerves. Infectious, inflammatory, congenital, and neoplastic lesions can occur in Meckel's cave. Leptomeningeal metastasis of glioblastoma (GBM), IDH-wildtype to Meckel's cave is rare. We encountered a case of leptomeningeal metastasis of GBM to Meckel's cave in an elderly female patient who presented with pain around her right eye. Magnetic resonance imaging revealed enhancing lesions in the right temporal lobe and cervical spinal cord. The pathological diagnosis of GBM was confirmed after biopsy of the cervical spinal cord lesion, which showed hyperaccumulation of fluorodeoxyglucose (FDG) on FDG-positron emission tomography. This case indicates that metastatic lesions can also occur in Meckel's cave.

High baseline total lesion glycolysis predicts early progression of disease within 24 months in patients with high-tumor-burden follicular lymphoma.

Despite the introduction of rituximab-containing regimens, approximately 20% of patients with follicular lymphoma (FL) still experience progression of disease within 24 months (POD24) and have poor overall survival. Therefore, a more accurate risk assessment tool is required. We investigated the predictive value of two new volume-based parameters determined from baseline 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT), baseline total metabolic tumor volume (TMTV) and total lesion glycolysis (TLG), in 45 patients with high-tumor-burden FL who underwent baseline PET/CT. We observed that high TMTV, high TLG, and poor initial treatment response (less than complete [metabolic] response [non-CR/CMR] at the end of induction therapy) independently predicted poor PFS. Notably, POD24-positive patients were more common in the high-TLG group than in the high-TMTV group, which suggests that TLG is a stronger predictor of outcomes than TMTV. Combining baseline TLG and initial treatment response showed that patients with both high TLG and non-CR/CMR experienced significantly poorer outcomes, with a 2 year PFS of 0% (hazard ratio 60.39, P = 0.000002). This combination had 56% sensitivity and 100% specificity for detecting patients who would experience POD24. Baseline TLG and initial treatment response can precisely identify patients at high risk of POD24.

Adult-Onset Acute Disseminated Encephalomyelitis with Epstein-Barr Virus Infection.

We present the case of a 22-year-old man who was diagnosed with tonsillitis and treated with antibiotics. Although the symptoms subsided, 1 week later, he presented with weakness in the lower limbs and was hospitalized. The weakness in the lower limbs worsened; he developed difficulty speaking and was transferred to our hospital. Laboratory tests showed a white blood cell count of 10,600/µL (24% atypical lymphocytes). Positive results were obtained for immunoglobulin M (IgM) antibody against Epstein-Barr virus (EBV) viral capsid antigen. EBV-deoxyribonucleic acid quantification in blood yielded positive results. Magnetic resonance imaging (MRI) revealed a hyperintensity in the spinal cord at the Th11 level of the lower spine on T2-weighted imaging (T2WI). In addition, T2WI and fluid-attenuated inversion recovery imaging showed hyperintense lesions on the right cerebral peduncle, bilateral thalami, posterior leg of the left internal capsule, and right corona radiata. We diagnosed acute disseminated encephalomyelitis (ADEM) with EBV and initiated steroid pulse therapy. Symptoms, along with the lesions seen on MRI, subsequently ameliorated. This case suggests that ADEM can be difficult to diagnose, but careful diagnosis is crucial since appropriate treatment is necessary to improve the symptoms.

New PET/CT criterion for predicting lymph node metastasis in resectable advanced (stage IB-III) lung cancer: The standard uptake values ratio of ipsilateral/contralateral hilar nodes.

BACKGROUND: The aim of the present study was to use surgical and histological results to develop a simple noninvasive technique to improve nodal staging using preoperative PET/CT in patients with resectable lung cancer. METHODS: Preoperative PET/CT findings (pStage IB-III 182 patients) and pathological diagnoses after surgical resection were evaluated. Using PET/CT images to determine the standardized uptake value (SUV) ratio, the SUVmax of a contralateral hilar lymph node (on the side of the chest opposite to the primary tumor) was measured simultaneously. The I/C-SUV ratio was calculated as ipsilateral hilar node SUV/contralateral hilar node SUV. Receiver operating characteristic (ROC) curves were then used to analyze those data. RESULTS: Based on ROC analyses, the cutoff I/C-SUV ratio for diagnosis of lymph node metastasis was 1.34. With a tumor ipsilateral lymph node SUVmax ≥2.5, an IC-SUV ratio ≥1.34 had the highest accuracy for predicting N1/N2 metastasis; the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of nodal staging were 60.66, 85.11, 84.09, 62.5 and 71.29%, respectively. CONCLUSIONS: When diagnosing nodal stage, a lymph node I/C-SUV ratio ≥1.34 can be an effective criterion for determining surgical indications in advanced lung cancer.

Changes in Serum Trace Element Concentrations Before and After Surgery in Resectable Breast Cancer.

BACKGROUND/AIM: Minerals and trace elements (TEs) play vital roles in normal biological functions and in all cancers. Breast carcinoma is the most commonly occurring cancer in women. The aim of this study was to evaluate changes in TE levels before and after breast cancer surgery and the clinical utility and reliability of TE levels assayed using inductively coupled plasma mass spectrometry (ICP-MS). PATIENTS AND METHODS: Thirteen patients with ductal carcinoma in situ (DCIS) and 34 with invasive ductal carcinoma (IDC) treated with planned surgery were enrolled between August 2017 and February 2019. Blood samples were collected before and the day after resection of the primary tumor. All enrolled patients received mastectomy or quadrantectomy and axillary lymph node dissection/biopsy. Serum TE concentrations were determined using ICP-MS. RESULTS: Changes in boron, titanium, vanadium, chromium, copper, zinc, and selenium levels from before to after surgery differed between IDC and DCIS patients. Boron and copper levels before surgery and changes in titanium, vanadium, and chromium before and after surgery are potential predictors distinguishing DCIS from IDC. Subset analysis showed that chromium is a potential biomarker for luminal subtype, while titanium and chromium are potential biomarkers for pathological staging. CONCLUSION: Changes in serum TEs before and after surgery may help with diagnosis and staging of breast cancer and in establishing TE supplementation protocols.

A male with primary accessory breast carcinoma in an axilla is strongly suspected of having hereditary breast cancer.

We herein report on a male with primary accessory breast cancer in an axilla. A 75-year-old man first noticed a subcutaneous nodule about 2 cm in diameter in the area of his right axilla. The patient underwent extirpation of the mass in a public hospital. Histological examination revealed invasive breast carcinoma of no special type associated with mucinous carcinoma, invasive micropapillary carcinoma and intraductal components. Immunohistochemical analysis showed that the tumor cells were positive for Gross cystic disease fluid protein (GCDFP)-15, mammaglobin and GATA3. Staining for estrogen receptor (ER) and progesterone receptor (PR) was positive, and human epidermal growth factor receptor 2 (HER2) was negative. The Ki67 labeling index (LI) was 33.6%. Imaging revealed no evidence of a primary tumor in any other organ or in the bilateral mammary gland. We performed radical resection of the right axilla, including the scar, and axillary lymph node dissection. The final pathological examination of the surgical specimen showed normal mammary gland tissue that was not connected to the proper mammary gland, and no residual cancer or metastatic lymph nodes. Based on our clinical and pathological findings, this tumor was diagnosed as breast cancer originating from the accessory mammary gland in the right axilla. After surgery, tamoxifen was administered as adjuvant therapy. Since the surgery, 2 years ago, there has been no evidence of recurrence. Hereditary Breast and Ovarian Cancer syndrome was suspected in this case because the patient was a male with breast cancer, and he had two first-degree relatives with breast cancer. This patient had no BRCA mutations on genetic testing. Nonetheless, in cases of male breast cancer, it is necessary to obtain genetic information due to the possibility of hereditary breast cancer, including cancers associated with BRCA gene mutation.

Accurate diagnosis of peripheral small cell lung cancer with computed tomography.

Small lesions are frequently detected in the lung with computed tomography (CT) in clinical practice. It is important to know the CT features of small-sized peripheral small cell lung cancer (SCLC) for early-stage diagnosis. We reviewed the CT findings of SCLC that presented as a solitary peripheral nodule without associated lymphadenopathy. This study included 12 patients (11 men and 1 woman; mean age, 68.5 years) with peripheral SCLC of diameters ranging from 9 - 28 mm (mean, 15.4 mm). We evaluated the findings with thin-section CT for each peripheral tumor; emphasis was laid on the predominant internal characteristics (whether the mass is solid), tumor-lung interface characteristics (whether the mass is well-defined with a smooth surface or with lobulation or spiculation), and surrounding structures (the presence or absence of perivascular thickening adjacent to the tumor). In all patients, most portions of the tumor consisted of a non-calcified solid mass. Contrast enhancement in varying degrees was observed in the tumors of all 8 patients, who were evaluated with enhanced CT. The tumor-lung interface characteristics observed on the CT images included a well-defined mass with a smooth surface (n = 5), a well-defined mass with lobulation (n = 3), and a mass with spiculation (n = 4). An irregular perivascular thickening adjacent to the tumor was observed in 4 patients. We conclude that peripheral SCLC without associated lymphadenopathy manifests as a non-calcified solid mass and is occasionally characterized by perivascular thickening.

Sentinel Lymph Node Biopsy Using Preoperative Computed Tomographic Lymphography and Intraoperative Indocyanine Green Fluorescence Imaging in Patients With Localized Tongue Cancer.

IMPORTANCE: The indocyanine green method alone is unsuitable for sentinel lymph node biopsy in patients with oral cancer because of poor transcutaneous identification of the fluorescent signal through the platysma and sternocleidomastoid muscles. OBJECTIVE: To assess the utility of a novel sentinel lymph node biopsy technique using preoperative computed tomographic (CT) lymphography followed by the intraoperative indocyanine green fluorescence method. DESIGN, SETTING, AND PARTICIPANTS: In this prospective study performed at Akita University Hospital, Akita, Japan, participants comprised 18 patients with previously untreated cN0 tongue cancer (squamous cell carcinoma) were enrolled from November 2012 to November 2016. Median observer period was 38 (range, 14-62) months. Analysis was completed between January 10 and March 10, 2018. INTERVENTIONS: For preoperative sentinel lymph node mapping, CT lymphography was performed the day before sentinel lymph node biopsy. For sentinel lymph node biopsy, a minimum skin incision was made according to the predetermined location of sentinel lymph nodes. Sentinel lymph nodes were excised under indocyanine green fluorescence guidance. MAIN OUTCOMES AND MEASURES: Identification rate of preoperative sentinel lymph node mapping by CT lymphography and the number of sentinel lymph node successfully identified by the intraoperative indocyanine green fluorescence method. RESULTS: Among 18 patients (8 men, 10 women; median age, 65.5 [range, 40-83] years), sentinel lymph nodes could be mapped by preoperative CT lymphography in 16 patients (89%). At least 1 sentinel lymph node was successfully identified and excised in each of these 16 patients using intraoperative indocyanine green fluorescence. Among the 16 patients in whom sentinel lymph nodes were excised, metastases to sentinel lymph nodes were found in 5 patients (31%). CONCLUSIONS AND RELEVANCE: The novel sentinel lymph node biopsy technique of preoperative CT lymphography mapping with intraoperative indocyanine green fluorescence has a high potential for identifying sentinel lymph nodes in patients with cN0 tongue cancer. Because the intraoperative indocyanine green method alone cannot identify sentinel lymph nodes in the neck region, this combined method has clinical potential as a sentinel lymph node biopsy technique that does not require radioisotopes.

Postmortem computed tomographic features in the diagnosis of drowning: a comparison of fresh water and salt water drowning cases.

PURPOSE: To investigate the effectiveness of postmortem computed tomography in the diagnosis of drowning, focusing on the comparison of fresh water and salt water cases using three-dimensionally (3D) reconstructed data. MATERIALS AND METHODS: We examined features of drowning in 25 fresh water drowning cases (FWDCs; 13 men, 12 women; mean age 73.1 years; range 43-95 years), and compared these with 12 salt water drowning cases (SWDCs; 5 men, 7 women; mean age 66.0 years; range 55-77 years). Pulmonary opacities, volume and density (CT number) of accumulated fluid in the paranasal sinuses and central airways, volume of the stomach/stomach contents, and cardiac blood density were examined. RESULTS: In SWDCs, pulmonary ground-glass opacities with wholly thickened interstitium was frequently identified (P = 0.0274). Whereas in FWDCs, a significantly larger volume and lower density of fluid in the paranasal sinuses (P = 0.0195 and P = 0.0104, respectively), lower density of fluid in the central airways (P = 0.0077), lower stomach content density (P = 0.0216), lower density in the left atrium (P = 0.0029), and a difference of density between the atria (P = 0.0247) were observed. CONCLUSIONS: A lower density in the left atrium was observed in FWDCs compared to SWDCs. This finding may be helpful in differentiating between FWDCs and SWDCs.

Correction to: Postmortem computed tomographic features in the diagnosis of drowning: a comparison of fresh water and salt water drowning cases.

Whereas in FWDCs, a significantly larger volume and lower density of fluid in the paranasal sinuses (P = 0.0195 and P = 0.0104, respectively), lower density of fluid in the central airways (P = 0.0077), lower stomach content density (P = 0.0216), lower density in the left atrium (P = 0.0029), and a difference of density between the atria (P = 0.0019) were observed.

Analysis of computed tomography density of liver before and after amiodarone administration.

PURPOSE: To evaluate CT density of liver changes between before and after amiodarone administration. MATERIALS AND METHODS: Twenty-five patients underwent non-enhanced CT including the liver before and after amiodarone administration. We set regions of interest (ROIs) at liver S8, spleen, paraspinal muscle, and calculated average CT density in these ROIs, then compared CT density between liver and other organs. Statistical differences between CT density of liver and various ratios before and after administration were determined, along with correlations between cumulative dose of amiodarone and liver density after administration, density change of liver, and various ratios after administration. RESULTS: Liver density, liver-to-spleen ratio, and liver-to-paraspinal muscle ratio differed significantly between before and after amiodarone administration. No significant correlations were found between cumulative doses of amiodarone and any of liver density after administration, density change of liver, or various ratios after administration. CONCLUSION: CT density of liver after amiodarone administration was significantly higher than that before administration. No correlations were identified between cumulative dose of amiodarone and either liver density after administration or density change of liver. Amiodarone usage should be checked when radiologists identify high density of the liver on CT.

Usefulness of circumference difference for estimating the likelihood of malignancy in small solitary pulmonary nodules on CT.

OBJECTIVE: The presence of a small solitary pulmonary nodule (SSPN) is a common finding on chest computed tomography (CT); however, preoperative diagnosis of SSPN is often difficult. We measured the extent of ground-glass opacity (GGO) and our own original method of circumference difference (CD) as an additional approach in classifying SSPN revealed on CT, and evaluated the likelihood of malignancy. METHOD: In total, 214 single SSPN with diameter <15mm were studied. All SSPN were histologically examined with surgical resection; preoperative CT findings and pathological diagnosis were evaluated retrospectively. The extent of the ratio of GGO and CD was evaluated using NIH image, where CD is defined as the ratio of the nodule margin distance to the circumference of the predicted circle with an area equal to that of the nodule. RESULTS: The thresholds for differentiating SSPN are 70% of GGO and 68% of the CD ratio. Differentiation of malignancy from benign tumor using our algorithm had sensitivity of 96.6%, specificity of 86.1%, and positive predictive value of 94.1%. CONCLUSION: Combined with other malignant likelihood parameters such as extent of GGO, CD ratio is a useful additional factor for estimating the likelihood of malignancy of SSPN on CT.

Preoperative mapping of lymphatic drainage from the tumor using ferumoxide-enhanced magnetic resonance imaging in clinical submucosal thoracic squamous cell esophageal cancer.

BACKGROUND: In thoracic esophageal cancer, lymph node metastases distribute widely from the neck to the abdominal area as a result of a complex periesophageal lymphatic network. The aim of the present study was to evaluate the potential clinical utility of a new method of mapping lymphatic drainage from tumors using ferumoxide-enhanced magnetic resonance imaging (MRI). METHODS: Twenty-three patients with clinical submucosal thoracic squamous cell esophageal cancer were examined. Ferumoxides were injected endoscopically into the peritumoral submucosal layer, after which their appearance in the lymph nodes in the neck, superior mediastinum, and abdomen was evaluated using MRI. RESULTS: Flux of ferumoxides from tumors was detected in all 23 patients. Among the 20 patients with middle and lower thoracic esophageal cancers, there was no lymphatic drainage to the neck in 5 (25%) patients, none to the neck and superior mediastinum in 4 (20%), and none to the abdomen in 2 (10%), which could enable the extent of lymph node dissection to be reduced. We diagnosed clinical negative lymph node metastasis (N0) in 17 patients; the remaining 6 patients were diagnosed with clinical lymph node metastasis. Two patients (12%) diagnosed clinical N0, showed pathologic lymph node metastasis. Ferumoxide-enhanced MRI detected an influx of contrast agent into the metastatic node in both patients. CONCLUSIONS: Ferumoxide-enhanced MRI lymphatic mapping enables detection of the direction and area of lymphatic flux. It thus has the potential to improve our ability to gauge the appropriate extent of treatment in clinical submucosal squamous cell esophageal cancer.

CT features of pancreatic fistula after pancreaticoduodenectomy.

OBJECTIVE: Our objective was to establish the CT features that are indicative of pancreatic fistula after pancreaticoduodenectomy. CONCLUSION: A fluid collection seen on CT around the pancreaticojejunostomy site and in the pancreatic bed may be caused by pancreatic fistula in patients who have undergone pancreaticoduodenectomy. CT depiction of air bubbles in the fluid at these sites may strongly suggest the diagnosis of pancreatic fistula.